[R] Read text file subsetting rows

[Zev Ross]

Hi All,

Can anyone direct me to a read function in R that will allow me to only 
read in rows of a text file that begin with a particular value such as 
the data below. I would read the entire file in and then limit, but the 
files were constructed such that the first two letters determine how 
many variables are in the row (different letters mean different numbers 
of columns and different column names/types).

I can do this in SAS, but I'd prefer to use R. The approximate SAS code 
is below with the key piece of code being "if rectype='RD'" then do.

Thoughts?

Zev


RD|I|01|073|0023|68103|5|7|017|810|20070103|00:00|0.6||3|||||||||||||
RD|I|01|073|0023|68103|5|7|017|810|20070106|00:00|9.5||3|||||||||||||
RD|I|01|073|0023|68103|5|7|017|810|20070109|00:00|2.5||3|||||||||||||
RD|I|01|073|0023|68103|5|7|017|810|20070112|00:00|13.7||3|||||||||||||
RD|I|01|073|0023|68103|5|7|017|810|20070115|00:00|7.3||3|||||||||||||
RA|I|01|073|0023|A334|5|7|017|810|20070118|00:00|3.7||3|||||||||||||
RD|I|01|073|0023|68103|5|7|017|810|20070121|00:00|6.9||3|||||||||||||
RC|I|01|073|0023|Quer|5|7|017|810|20070124|00:00|1.8||3|||||||||||||


infile 'C:\junk\RD_501_88101_2006-0.txt'
 dlm='|' firstobs=3 missover;
 rectype $2. @;
if rectype = 'RD' then do;

-- 
Zev Ross
ZevRoss Spatial Analysis
303 Fairmount Ave
Ithaca, NY 14850
607-277-0004 (phone)
866-877-3690 (fax, toll-free)
zev at zevross.com